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MEE-@H55 Nov. 2o, 1923.

R. G. RICHARDSON AUTOMATIC TELEPHONE SYSTEM Flled June 99 1917 Sii)Patented Nov. 20, 1923.

RODNEY G. RICHARDSON, GF CHICAGO, LLNO-S,

COMPANY, OF CHCAGO, ILLINO lia,

.PATENT FFCE.

SSEGITOL TO AUTGMATIC ELECTRIC Jil. CRPUIJATIQN OF ILLINOS.

AUTOMATXC TELEFIEEGNE SYSTEM.

Application filed .Tune 29, l'i?.

To o'/ whom 'it 'may concern.'

Be it known that l, Renner G. RICHARD- son', a citizen of the United`States ol' rimerica, and a resident'ot Chicago, county ot Cook, andState ot Illinois, have invented certain new and useful Improvements inAutomatic Telephone Systems, ot which the 'following is a s oeciication.

My invention relates in general to automatic telephone systems, in whichconnections are established automatically through the medium ofautomatic switches at the exchange, and involves a number of features,among which may be mentioned the provision of new and improved circuitsfor individual line or trunk selecting switches; the provision ot' newand improved circuits for selector' switches; the provision of new andimproved connector switches of large ca- `pacity and well adapted forstraight line or party line service; and the provision of a new,improved, and much simpliiied system oi' selective ringing .torautomatic party lines .vhich, although especially designed 'tor use in asystem employing my improved connector switches, may also he used withconnectors oi' other types.

The apparatus and circuits involved in carrying out the foregoing andother useful objects will be fully described and explained hereinafter,reference being had to the accompanying drawings, in which Figs. l and 2when taken in order with corresponding lines at the ends thereof inalignment.` represent diagrammatically a complete circuit connectionbetween a calling substation A and a called substation A in a systemembodying the principles of my invention; while Fig. 3 shows thenumbering of one o'i'i the hanlr levels ot my improved connector switch.

Referring to Fig. l of the drawings, the si .istation Ar may be of anyapproved automatic type such, for example, as the one disclosed in theBritish ,Patent to Martin, No. lei-1,9 of 1910. ris illustrated, itcomprises essentially the receiver il. transmitter 3, switchhook Ll,ringer 5, and condenser o. Being an automatic substation, there is alsoprovided a pair of impulse springs 7 and 8 which may be controlled bythe impulse wheel 9 through the medium` of a linger hole dial (notshown).

The line conductors l2 and 13 extend to the exchange where theyterminate in 'thc Serial ilo. 177,653.

individual line switch C, in a manner to be descril ed more tully inconnection with the shone'- of the called line in Fig. 2. The lineswitch C may be briefly described as a rotary line switch whose movableterminals or wipers have no normal position and have movement in aforward direction only. A construction which permits oli the continuousLioiwvard movement of the line switch wipers is illustrated in the ll.S. Patent to Dietl No. 1,126,727. l prefer, however, to use doubleinstead of 'triple wipers, and a banlr conijrising 25 bank contact sets.l provide an improved circuit for a rotary line s vitch ot' thischaracter, whereby ordi.- nary manual relays may loe used having nomechanical connections between their arn'iatures.

Three hundred Or more oi2 these individial line switch is may he givenaccess to a group ot 25 trunk lines, each or which trunk linestern'iinates in iirst selector switch tin@ o'l the trunk lines. toYwhich the iiidivid ual line switch U has access., is the truuk linecP-Lcuding to the :first selector lll l), which may he ot the generaltype of silector switch shown in the patent to ieith,

'ichsoin and Erickson, No. 815,321, granted March 1 3, 1906. The sideswitch and private magnetomitted, hows-Jan', and the circuits aremodilied in accordance withl the tivo wire system oii control.Vlilurther modilicationsl in accordance \l h my invention provide anexceedingly simple and ethcient circuit tor a selector switch ot 'thischaracter, will be iully explained hereinafter.

giianted Vial-ch lil. 1906, to lSi-ith` Erickson, and iriclson, exceptthat the circuits are modifi-l in accordance with modern two wirepractice. as in the case of selector l, and furthew modified in order toaccomplish the objects or my invention, as will he tully explainedhereinafter. There are also some slight mechanical diilerences. Insteadot th 3` usual three position side switch, the sidl switch on myimproved connector has te positions, the escapenient springs controlledby the private magnet being each orovided with an extra notch. There isalso provided, in addition to the usual vertical otinormal springs, apair ot rotary ott-normal. spriiws, indicated'by reference characters 24and l J3, which are closed upon thesecond rotary step ol the shaft. tshould be mentioned also that the connector shaft is provided withsullicient teeth in the rotary ratchet portion thereof to enable it totake twenty ro tary steps instead of the usual ten.

The bank of my improved connector switch is similar to the bank shown inthe patent to Keith and the Ericksons above mentioned, that is, it iscomposed ot contact sets arranged in ten horizontal rows or levels. Eachlevel, however, instead ot having ten contact sets, has twenty Contactets, thereby giving the connector a capacity or tivo hundred lines.Although physically the entire two hundred lines accessible to a groupof connectors may be considered as comprising a single group, nevertheess, since the usual decimal numbering and trunking scheme is used, theyare tor numbering purposes divided into two groups ot one hundred lineseach. rlhese l term thcl odd hundred and the even hundred, or the onehundred and the four hundred. Contact sets in the two hundreds aredisposed alternately in the connector bank. Thus, referring to Fig. 3,which shows the numbering ot the first level, the first level contactsets o1" the one hundred, being contact sets numbered from lll to 110,inclusive, are the lirst, third, lilith, seventh, etc., contact sets inthe level, while the lirst level contact sets of the four hundred,comprising contact sets numbering from Llll to dell), inelusive, are thesecond, fourth, sir-1th, eighth, ctc., contact sets. It will beunderstood troni the foregoing, that the third from the last digit inevery telephone number is either 'l or 4f. In considering the trunking,this digit may be neglected; and it may be stated that the trunking inthe system shown i' precisely the same as in the usual and well knownthree digit percentage system, the exra digit being inserted simply tocoY rol the idd or even hundreds selection at the conlt will beunderstood, hor-fever, that since each `Oroup oit connectors has arcessto two hundred lines instead otl to one hundred, there must be provideda larger number of connectors in each group. To take care otvthis theselector switches are preferably provided with two hundred point bankslike the connectors. Fifteen or sii;- teen contact sets or as many asare necessary to handle the trallic may be usen in each level.

The bank wires from each group oft connectors, commonlj,7 called normal.conductors, are termed into cables and entend Ato and terminate on thehorizontal side ot' an intermediate distributing traine D. lh), wherethe odd and even hundreds of each group are preferably separated, tbenormal conductors from reach iundred being arranged in consecutiveorder. ln general the preferred arrangement ot the main and intermediatedistributing 'trames and the cross connecting scheme used is similarclosure in the Australian ljatent ot i920. ln the drawing the contac`prising bank contacts lb l sinned to be an odd huinired contact set inthe lirst level, and its normal conductors terminate in the terminalsi90, lill, and lQQ on the horizontal side or' the l l?. rEhe contact setcomprising bank contact sets lSG, 18.7, and 188 is assumed to be an evenhundred contact set in the sec-ond level, and its normal conductorsextend to terminals i93, 194i-, and 195 on the horizontal side et the l.D. F. The drawing being purely diagrammatic, does not show the relativeposition ot' the terminals but only the connections. As illustrated, thetwo sets oli nornial conductors serve as called line branches tor theparty line ZlQ-Zl, which has two substations fr and rvhe location ot thevarious terminals shown and their connections are as follows: Theterminals 202 and 203 are on the protector' side et the main trarne andare connected by means ot a duplex jumper with the terminals 20() and:201 on the switch board side ot the main frame. These latter terminalsare connected by a cable pair with the terminals 196 and 198, which arethe line terminals of the terminal set comprising terminals 195, ll?,and i9?, located on the vert-ical side oft the l. l). l". lirom thethree terminals ot th's set, conductors 20d, 205, and entend to an iediidual line switch iilar to the line s i e l). lr' branco et e line andprovides 'lor outgoing service. nce the line shown is a two pai-tv line,two lied line branches will. be ret` d to turnish ncoming service, andit has been previously assumed that the branches to be used are the onesconiprisi` the lwe sets et nt mal conductors shown. Terminal alslfll-llllml and 'lQOwiQW-ll are cordingly connected by' means ol triplexiumpers to the terminal set lQG 'lQTfQzt There being only ti i jumpersto be multiplied, they niay l Y ectxi direct to terminal set llfl l,anc1 seiL arate multiple or idler7 termi al blocks need not be used.iilhile tor convenience both ot the called line branches et the partyline 212-213 have been shown extending from the same group oficonnectors, it will be understood that by the provision ot theintermediate distributingframe the party flii lill) line may just aswell be connected up to be called troni different groups of connectors.In other words, in connecting` up a party line tor service, it is onlynecessary to choose an odd hundred call nuinber and an even hundred callnuniber, without regard 'to whether the two hundreds are in the samegroup of connectors or not.

lVhile I have shown throughout the 'awing a plurality of batteries, it vi be understood that in accordance with the usual practice there ispreferably but one central battery having its positive pole Associatedwith the connector i-, shown a busy signaling niachine Q5, a ringinginterrupter IR, and generators Gen1 and len? The busy signaling machineand the ringing interruptor are ot the type used in well known automatictelephone systeins and need not be described in detail. rlhe generatorsGen and Gren2 preferably deliver alternating;u current diiiering; infrequency,

and providing for selective ringing; on the well known harmonicprinciple.

Having given a brietY description of the apparatus involved, l will newproceed to an explanation et the operation thereof. For this purpose itwill be assumed that the sulfiscriber at substation A desires to obtaina connection with the subscriber at substa tion A, this beingl thecomplete circuit connection shown lin the drawings. The tele: nhonenumber ot substation is 3115. litter describing; the establishment andre lease of the above connection, an explanation will be made oit theoperation of the connector H in calling the substation A2, telephonenumber 3425, which substation is on the saine line with substation A.

To proceed, when the subscriber at substation A removes his receiver toinitiate the call, au energgiZingA circuit completed the line relay ldet the indiif'idual line switch (l as follows: ground at G', restingcontact ot arnriture 19 and the said armature, conductor l2, substationA, conductor 1S, armature 2() and its resting Contact, and the winding`relay IlG to battery.

Upon energizing, '1.6 closes the following circuit: ground at iig. ature and its working` Contact. ywinding of switching` r A l, winding oitcutoff relay l5, and the pping magnet to battery. Simultaneously withthe closure et the above circuit, the line relay 1G connects the privateor test wiper /l-l with the iunction point 30 as iiolli'nvs: test wiperdl. arrnature il and its resting); contact, working` conot armature 22and the said ain'iatin'e junction point 550. .it is understood at thewipers of the line switch are nortlly in engagement with sorne contactset in the bank. and the operation depends upon 'whether' the contactset upon which the wipers are now rest-ing is busy or not. li thisContact set is busy, the test contact ein] LLM batterj rlhus it u'iil beseen that the relays le an will bc short clrcuited by ground potentialapplied to the upper terminal or' relay l5 by way ot junction point 30as long;` as the wiper lll ein, ses busy or @rounded 00 contacts. By theenergization ot the steppiugiv niagnet 18, the switch wipers areadvanced to the next contact set, and since the stepping magnetinterrupts its own circuit, V the advance oi. tbe wipers will becontinued through the \f'ibratory operation of the stepping magnet aslongY as the test wiper el continues to engage grounded or busy testcontacts. lihen an idle or ungrounded test contact is reached, which wewill assume to J contact lill, the operation ot the be the test steppingmagnet will cease; and the relays and 17 being` no longer shortcireuited, will energize over the previously traced eircuit extendingfrom ground G2. Relays l5 95 and 17 are ot sutlicient resistance toprevent the eni Vfixation ot the stepping` magnet li. ly the conjointaction oi the cut-olil relav l5 and the switching relay l? the incoming;line conductors l2 and lil are disconnected 100 respectively Ytroniground G and the windinir et the line relay 16 at the line switch C, andare extended by way of line wipers 42 and il-0, banlr contacts ll5 andd3, anu norinally closed contacts of the switching' relay 53 tio 105ground G3 and the winding` of the line relav O of the selector E. Theswitchingrelay i7 also has the function olli shifting the counect' ofthe test wiper ll, whereby the test wiper is connected to the upperterminal of the said relay 17.

ldihen the conductors of the calling line extended to the `firstselector E, the line relay 5G of the selector is energized over the gsubscriberas loop and completes the 115 ed energizing circuit ttor tbeslow acting e relay Relay 5l, upon energizingi, pietes a holding`circuit tor the relays ind l1? ot the line switch C as follows:

ground at G5, working contact of armature 120 n2 z: nd the saidarmature, conductor 46, bank way ot conductor 28 to inultiple test contaf, in the banks of the connector switches which have access to theline el substation Relay 17 is oit lower resistance than relay 15 andthese test contacts are brought lliciently near to ground potential torender the lino of substation A busy. Although do not restrict myself toany particular -.'alues, relay resistances which e goed resalts inpractice are follows: relay l5, S00 oli s; relay 1G, 500 ohnis; andrelay l?, 200 ohms. rlie stepping inagnet it, ot course, is etcomparatively low esistance, preteraoly oi about 40 or 50 ohms.

Returning to the selector E, when the conductor 4G was grounded by theenergizaton o'j relay 5l, circuits were closed simultaneously throughthe upper' and lower wiiidings ot switching relay 53. rvl'he circuitthrough the lower winding extends troni grounded conductor 4G by way otjunction point 68, the letthand interruptor contact ot ihe rotaryinagnet 50, arinat; 52) and its resting contact, and the lower windingof relay to batter ylie circuit through the upper Winding is a branch orthe above circuit beginning at the junction point ltelay 53 isdifferentially wound and there-- lore is not energized at this tinie.

The foregoing operations have all occurred in response to the removaloit' the receiver at substation rl. The calling subscriber niay newoperate his calling device in accordance with the lirst digit ol' thedesired nuiiiber, thereby producing a series ot three interruptions inthe circuit ot the line relay 50 of the selector E. ln response to theseinterruptions oit its circuit, the line relay 50 is doenergized acorresponding nuniber ot times and at each dcenergization transmits auimpulse to the vertical magnet 54 as tollows: `ground at (tt, armatureG1 and its resting Contact, resting contact et armature 58 and the saidarmature, armature 03 and its working contact, winding t low resistanceslow acting relay 52, and the winding ot the vertical niagnot 54 tobattery. ln rcspense to these impulses, the Vertical niagnet is operatedto raise the selector switch shalt sten by step until wipers 80, S1, andarrive opposite the third horizontal level ol the baiilr contacts. Theslow acting relay 52 is energized in series with the Yertical magnet 54and retains its armature attracted dui-ir r the series ot' impulses inorder to hold open a circuit 'tor the rotary inagnet 5G which isprepared by the closure ot the o'tl-iioirnal springs 67 by 'thefirstupward nioveineiit or' the shaft. At the end of the Verticalincrement oi" the switch, the slow acting relay 52 is deenergized tocomplete the circuit of the rotary magnet 55 as tollows: ground at G5,working contact of armature 62 and the said armature, conductor 46,junction point 6.8, lelthand inter- Larnaca oit the rotary magnetl56,and its resting contact, arnia.- i ts working contact, arinature 65 'itsrcs'ng contact, righthand interntact of the rotary magnet 56 and ndingof the said magnet, and the or'l'- l springs 67 to battery. The rotary t5G is accordingly energized and the S0, S1. and arev rotated inteenwifnent with the li'rst set ot bank conin the level opposite whichthey are raised )Tear the end el the stroke, the rotary opens itsinterirptel contacts, L l;

herebj7 l reakiiig its own circuit and also the reviously traced circuitthrough the lower el vthe switching relay The operation now depends uponwhether the Contact set which isnow engaged by the selector wipers isbusy lor idle. lt this con- A'ie test wiper 81 "fill have a groundpotential upon it, .'.fl:ereupon current flow is inaintained'in thelower winding olE relay 553 regardless of the operation ot the rotarymagnet, the circuit being as follows: grouiidefl test contact, testwiper 8l, armature 59 and its resting contact, and the lower winding ofrelay 53 to batter Since the relay 53 does not energize under thesecircumstances, when tiie rotary niagnct 50 deenergizes, its energizingcircuit is rcestablished and the well known Vibratory action is set up,Jhereby the switch wipers are advanced step by step as long as the testwipe Sl continues to engage grounded or busy test contacts. lVhen anidle or ungrounded test Contact is reached, assuined to be the testconta -t S4, the instant the rotary inagnet 56 opens its lefthandinterruptor contact current will cease to flow in the lower winding otrelay There being now no opposition to the niagnetizing etlect of itsuppcrw'inding, relay 53 energizes at once and at its arniaturc59 opensthe circuit of the rotary magnet, whereby the turtlier advance ot' theswitch is prevented. rlhe relay 53 also opens a contact in the circuitotrelease inagnet 55 at its arniature 58 in order to provide against'therelease of the switch noon the deenergization ot relays 50 and 5l whichoccurs an instant later; and at its armatures 60 and 5T disconnects theline conductors 12 and 13 respectively, troni ground G3 and troni theline relay 50 and extends thein by way oiC line wipers 82 and S0, bankcontacts S5 and 83, and conductors 142 and 140 tothe line relays 100 and102 ot the connector ll (Fig. 2). The following circuit is thereuponestablished: ground at G7, lower winding oi'' relay 104,

winding ol relay 102, line conductor 142,

` set is busy, the test contact engaged by ductor l2, substation A, lineconductor 13, working contact of armature 23 and the said armature, linewiper 10, bank contact 13, armature 5T its working contact, line wiper,80, banlr contact 33, condi'ictor 140, and the winding of the iy 100 tobattery. Upon the closure of the i beve circuit, relays 100, 102, and104l energized in series. The cncrgization of relay 100 is followed bythe encrgizatiou of the slow acting release relav 101, which closes aholding circuit for the selector E and line switch C as follows: groundat G8, working contact of armature 118 and the said armature, conductorlll-1` bank Contact 34, test wiper 81, and ilie lefthand interriu'itercontact of the rotarj.' magnet 5G to iunction point 68, where it joinsthe previously described holding circuit extending 1oaclr to theindividual line switch C. The switching relay 53 is, of course.maintained energized over the branch circuit extending from junctionpoint 69 to its upper winding.

Returning to the connector H, the energization of the line relay 102 iswithout particular function at this time. The release relay 101, inaddition to grounding the conductor 1111 as described, also connectsground G8 to the junction of relays 102 and 104, thereby shortcircuiting the lower winding of the latter relay. Relay 104e does notdeenergize, however, to a locking circuit which has been establishedover the following path: ground at working contact of armature 118 andthe said armature, conductor 141, armature 123 its resting contact,armature 127 and its working contact, and the upper winding of relay 104to battery. When relay 10-1 is in energized position, the shortcircuiting path around the off-normal springs 12a and 125 is opened atarmature 126, and the ringingl current generator Gen is connected forservice at armature 128.

rPhe calling subscriber may now proceed to dial the second digit in thenumber of the substation A', which is the digit 1. It followsaccordingly, that a single interruption is produced in the energizingcircuit of the line relays 100 and 102, resulting in a singlemon'ientary deenergization of both relays. The deenergization of relay102 is of no effect; relay 100, however, transmits an impulse to theslow acting relay 103 over the following path: ground at (lo, armature117 and its resting contact, armature 119 and its working contact,winding of relay' 103, restingr contact of armature 131 and the saidarmature, and the low resistance primary winding of the busy signalingmachine Q to battery. Relay 103 ci'iergized .for an instant in responseto a momentary flow of current in the above circuit and at its armature123 closes a circuit for the private magnet 111 ifo'llfowsi lgroundedconductor 141, armature 123 and its working contact, and the winding ofthe private magnet 111 to battery. Upon the deenergization of the relay103 and the private magnet 111, the latter advances the side switchwipers 115 and 116 from first to second position in the usual manner. ltis to be noted that when the relay 103 is energized in response to thecalling of the digit 1, the locking circuit of relay 10-1 is brokenmomentarily at the resting contact of armature 123. Relay 104 is a slowactingl relay and is so adjusted that it will not deenergize when itslocking circuit is opened only momentarily as occurs under the presentcircumstances.

The calling subscriber may now operate his calling device in accordancewith the next digit of the desired number, thereby producing as beforean interruption in the energizing circuit of the line relays 100 and102. The consequent deenergization of relay 102` is again of no effect;but relay 100, upon deenergizing, transmits as previously an impulse tothe slow acting relay 103, and also, since side switch wiper 115 is nowin its second position, an impulse to the vertical magnet 109. Thevertical magnet 109 and the slow acting relay 103 are thereforeenergized in parallel. By the operation of the vertical magnet, theconnector shaft is raised one step whereby the wipers 180, 181, and 182are brought into position opposite the first horizontal level of bankcontacts. By the operation of relay 103, the private man? net 111 isactuated as before to advance the side switch wipers 115 and 116 fromsecond to third position. It should be mentioned at this point that atthe rst upward movement of the switch shaft the off-normal springs 113and 114 are closed in order to guard against a prolonged opening of thelocking circuit of relay 104, which would have taken place had the digitjust called been some digit other than the .digit 1, for the relay 103being slow acting remains energized continuously during a series ofimpulses. Thus it will be seen that relay 103 controls the lockingcircuit of relay 104 only during the first series of impulses which isdirected to the connector H and that during` subsequent series ofimpulses the said relav 104 will remain locked up independent of relay103 by way of off-normal springs 113 and 1111.

The calling subscriber may now call the final digit inV the number ofsubstation A', thereby producing a series of live interruptions in thecircuit of the line relays 100 and 102. The resulting deenergizations ofthe line relay 100, serve to cause momentary current impulses to flow inthe winding of relay 103, which relay being slowacting remains energizedcontinuously during the series of impulses and maintains an energizingcircuit for the privatemagnet 111. Side switch wiper 115 having movedJfrom serond to third position, the vertical magnet 109 is not nowactuated; but instead the rotary magnet 110 is operated under the control oi" the line relay 102 in manner now to be described. it the lirstdeenergization oT relay 102, circuit is closed to the rotary magnet 110as follows: ground at GS, working contact oi armature 118 and the saidarmature, conductor 1111, armature 120 and its resting Contact, armature129 and its resting Contact winding of rotary magnet 110 and-the sideswitch wiper 115 in third position to battery. The rotary magnet 110 isaccordingly operated to advance the wipers 180, 181, and 162 intoengagement with the lirst oi contacts in the iii-st leiel. At the nextdeenergization of relay 102, the same circuit is again closed tor therotary magnet, whereupon the switch wipers are ar vanced into engagementwith the second set o1? contacts in the first level. Upon the secondrotary step, the` rotary ott-normal springs 1.2/1 and 125 are permittedto close and it follows therefore that when the relay 102 is energizedimmediately tollowing its second deenergization, a circuit will becompleted tor the rotary magnet 110 over the 'following path: groundedconductor armature 120 and its workingcontact, arma-- ture .122 and itsworking contact, otlnorinal springs 125 and 124C, armature 129 and itsresting contact, winding ot the rotary net 110 and the side switch viper115 in third position to battery. The rotary magnot is accordingly one'ized to advance the switch wipers to the third set oit contacts in thelirst level. rPhe deenergization and energizetion of rela-y 102 inresponse to the third interruption ot its circuit likewise produces twoclosures ot the circuit of the rotary magiiet- 110, the circuit beingclosed once at the resting contact of armature 120 and again at theworking contact oli the saine armaturc. 1t will be seenlthen that therotary magnet will be operated once upon the first interruption of the`circuit ot the relay 102 and twice at each succeeding interruption.Since in the present case tive interruptions are produced, the switchwip rs will be adranced nine steps into engagement Yith the ninth set otcontacts in the Erst level which, by referring Fig. 3, will bc seen tobe the ones assofied with the substation A.

At the end of the tinal series ot impulses, the slow acting relay 103doenergizes and its upper armature 122 breaks the circuit ot the rotarymagnet. fit its lower armature 123, relay 103 breaks the circuit ot theprivate magnet 111, whereupon the said magnet is deenergized to advancethe side switch wipers 115 and 116 to fourth position, it being assumedthat the line otsnostation ifi was idle when called. i' 'the advance otthe side switch wiper 116 to its fourth position, an

ifiwreoe energizing circuit is completed for the cutoi'i reizy 15 ot theline switch associated it 1i D im i' n f u wm ri t with ,ic mmf ,inc asio om. ground a i fm, switch wiper 116 in fourth posit .te or test wiper181, bank Contact tor 206, winding ot cut-olf relay 1 i e winding of thestepping magnet i rlhe cut-oft relay 15, owing to its high resistance,is energized without operating the stepping magnet 18 and disconnectsthe line conductors 2011 and 205 om their normal battery and groundconnecliions in the line s vitch. rEhe advance of the siele switchwipers 115 and 116 to fourth position also closes an energizing circuittor the wiper switching relay 103 in an obvious manner and by theoperation ot this relay, signaiing circuit is completed which may betraced follows: ground at G11, generator Gen', ringing interruptor 11?.,working Contact oit armature 123 and the said armature, resting contactof armature 131 ,und the said armature, armature 136 and its workingcontact, line wiper 182, bank contact 185, terminals 192, 198, 201, and203-, line conductor 213, the ringer 5 and condenser 6 at substation A',line conductor 212, terminals 202, 200, 196, and 190, bank contact 133,line wiper 180, working contaft ot armature 135 and the said armature,armati]l e 132 and its resting Contact, lower winding oit the ringcut-off relay 107, and the central oilice battery to ground G12. ly the.operation of toe ringing interruptor lit, the generator Gen isintermittently disconnected and a booster battery substituted therefor,thereby producing an intermittent ringing oi the bell at substation A.The relay 10.7 is so adjusted that it will notv energize so long as thereceiver at the called substation remains on the hook.

Yfhen the called subscriber at substation A. takes down his receiver inresponse to the ringing otl his bell, the ringl cut-off relay 107 in thesignaling circuit is instantlyY energized, irrespective oi? the positionot the ringing interruptor 1R, and completes a locking circuit toi'itsel't as follows: ground at G13, the lower pair ot oitnornial springs,working contact oi armature 133 and the said armature, and the upperwinding oi the relay 107 to battery. As fi further result of itsenergization, relay 107' disconnects its lower winding and the leadtroni the ringing current generator at its armatures 132 and 134respectively, and at the working contacts ot these same armatures iiicompletes the talking connection to the called line. n

supplie( l through the windings ot the line relays lll l and 102. Thepath o'l the voice currents has been draw; in heavy lines and willrequire no detailed explanation.

,frt the end of the conversation both subscribers will replace theirreceivers. By the replacement oi" the receiver at substation A, theenergrizimq` circuit et the line relays 100 and 102' el the connector His broken. The resultingdeeneruization or" the line relay 100 isifolloned alle' a brief interval by the deenergrization oi. the slowvacting relay 101, resultinp` in the closure et the circuit ot therelease ma gnet 112. The connector H is accordingly restored to normalposition th oungh the niediuin of the release magnet l 1. L asi-usual,the circuit ot the release magnet being opened when the switch shaftreaches its lowest position. As a further result of the deenergizationof relay 101, ground G8 is disconnected lroin conductor 141, therebyopeninrg` the holding).` circuit over which the relay 58 oit selector Eand the relays 1 7 and 15 of the line switch C have been maintainedenergized. Upon the deenergization ot relay tbe circuit ot' the releasemagnet 55 of the stlector is completed and the selector lli is thereforerestored to normal position in the same manner as Was the connector H.The .leenergjization ol relays 17 and 15 ot the line switch Cdisconnects the line of substation A from the line Wipers oil' itsindividual switch and places the switch in condition Ylor another call.All the apparatus involved in the connection has new been restored tonormal position.

l will new explain brieily the operation ot the connector I-l when thesubstation A2 is walled, in order that its operation in calling an evenhundredV station may be understood. A\ssnniingl that the telephonenumber at substation A? is 8425. the first series ol' impulses directedtmvard the connector ll will consist oi' Vtour interruptions ot the linecircuit Viuchulinpv the line relays 100 and 102, con resi'iondingf withthe digit 4 ot the called number. The line relays Will accordinglyieener`- me momentarily tour times, resultingr in the transmission bythe line relay 100 o t a series ot 'tour impulses to the slow actingrelay 108. The slot7 acting relay 108 during the continuance ot theseries of im pulses maintains its armature continuously attracted, andas betere described, closes an cnergjizinc,l circuit vtor thc privatemagnet 1 l1 and opens the locking' circuit ot the slow acting,- relay1011. At the end. of the series ot inuiulses, relay 108 and private.magnet 111 deenergrize and the ,side switch is advanced by the latterto second position. In the case where the substation A. Was the calledsubstation, the VErst series ot impulses directed.

to the connector H consisting' ot a single interruption ot the linecircuit, it Was explained that the resulting energizatlon ot as not otsufficient duration to bring about the deenergization oi'' the slowacting` relay 104. ln the present case, however, since the digit calledis 4l instead ot 1, the relay 108 will remain energized lour times lonas in the former case, thus insuringg` that relay 10e will deenergize.Upon retracting armatures, relay 10e breaks its own locking circuit atarmature 12T so that it cannot again energize during the rame call;short circuits the oil-normal springs 124 and at armature 126: and atits armature 128 connects the ring# ing current generator Gen'l. Vlhe`vertical operation ol the connector in response to the next digit oi1the number is the same as before. llhen the final digit is called, sincethe rotary off-normal springs 1211 and 125 have been short circuited,the rotary magnet 110 will receive two impulses tor each inA terruptionoi the line circuit, including the first interruption as Well as theremaining` ones. 1t follows that the switch Wipers 180, 181, and 182will be advanced ten steps into engagement with the Contact setcomprising,r bank conta-cts 186, 187, and 188, which is the Contact setassociated with the substation A?. During the signaling operation, thegenerator Gren2 is in service, resulting` in the actuation of the ringer52 at the substation A2, the ringer 5 at substation Al not beingoperated. llllhen the subscriber at substation A2 responds, the ringingcurrent is cut oft and the talking connection is cornpleted bei'oredescribed.

lt in callingcither substation A or ft2, the called line had been busy,there would have been a ground potential on test con.- tact 181. llnderthese circumstances when the slow acting relay 108 deenergizes at theend oit' the linal `cries of impulses, its decneigization is not.iollowed by the decn4 e i but relay 108 .c

nation ot' the private magnet lll; l l.

alter isinaintained energized over the test circuit extending asfollows: grounded 'test contact 1811, private or test wiper 1.81, sidesui'ch wiper 1.16 in thin.`1 position, contact si 'ings controlled bythe armature .1f-l0 oil te relay 105, yv'ii'idinl o? the tm" l/(mrli'relay, ontrct springs controlled by the ar- 128 ci relay 108.. and thewinding private magnet 1.11 to battery. Upon nini-agg. the test relay105 completes a ig* circuit tor itscll and the private `-t 111: opensthe circuit of therotsn'y ina 110 it its armature 129; and at its ri. eYlS-l opens the ciruit ot relay 108 rf reni is the primary i. ding' etthe induction coil oit Yhe busy signaling' machine l the lor,r learylinc conductor. The thereby given a cliarachave devised an automatictelephone containing a, number of Vfeatures conducin to Ls increasedliulness and elliciency. While l have shown :ind described a speciliceiuliuodimcnt el the rarious 'licafures i lications may made withoutdejoai'tn 'from the ,si-op' `pie invention. ample, a group oitconnectors such as the connector ll, is not necessarily restricted toparty line service, but an7 set oi bank con- 'acts in eithe the odd oreven hundred may be cross connected at the intermediate distrihuting''tra-nic to an individual line, it heing only necessary to install asuhstation cn the line which has a tuned to the proper frequency. Or

it desired untuned rlngers 1 ay be used on the individual lines whichwill respond to either 'frequency of ringing# current, thus making itunnecessary to consider this detail at all. liloreover, ii' the exchangeconsists entirely of individual lines, the party line and selectiveringing' features may be cut out altogether. ln an installation ot thischaracter, the intermediate distriluitiugr traine will be discarded, thenormal conductors 'from the connector hanls heini! terminated directlyon the switch hoard side oli the main distributing` traine, and thetrequency selecting armatures ot the connectors such as the armature 12Sof the connector l'l being` omitted. lt 'fill be ob vious also thatl theselective ringing feature ot the invention will oli utility when usedwith the ordinary connectors of one hundred line capacity. Connectorsthus equipped may be similar to the connector l-l except that they willhave the ordinary one hundred point bank and that the circuits provided'for the doubling' up ot the impulses to the rotary mao'net will heomitted.

ln view ot these considerations, li do not wish to have the inventionrestricted to the precise term shown and cl-,escril'ied` but desire toinclude and have protected hy Letters Patent all 'lorius andn'iodilicalions thereof which come within the scope ot the appendedclaims.

l'vilhat ll claim as my invention is:

l. ln a telephone system, a suloscribe1"s line having' an individualtrunk selectingY switch at the exchange, line, cut-ott, and lineswitching' relays in said switch, a stepping iiizrg'iirtn and a circuitcompleted hy said line relay in rcspo se to the removal of the receiverat the substation on said line., said circuit including' the other tworelays and said magnet in series,

2, ln a telephone system, a subscribers line havincj an individual trunkselecting' switch at the exchange, line, cut-oil, and line switching'relays in iid switch, a stepping' magnet, a. circuit completed by saidline relay in response to the removal ot the re ceiver at the substationon said line, said circuit including the other two relays and said saidmagnet in series, a test wiper in switch, and a branch oi'i said cir "tcompleted hy said line relay und -l 'from a point 1netiveen the saidmagnet and cui-ell relay to the said test wiper. c TU ln a telephonesyslem, line extending' to an exchange and pro ide-il with calling' andcalled branches there an individual trunk selecl 'in' switch ifextending' the calling' branch and trunk lines accessible 75 thereto,cut-ott and line si lchinc' relays in said switch, third conductors'ociaicd with the called hranch ol said lY i with the several trunk liies, an W c' tor hoth said relays completen conductor ot a selected trunkline whe line is calling, and an energizing' circuit the said cut-oilrelt'i v alone comple/time` the third conductor ot the called branchwhen the line is called.

4. in a telephone system, a line provided with an individual trunkselecting' switch at the exchange, a line relay controlling' theoperation of said switch, a switchingrelay for closing' contacts in the.line circuit atter said switch has operated, a cut-ott relay tordisconnecting` said line relay, and an energizing' circuit including'said cut-ott and switching' relays in series.

5. ln a telephone system, a liuc provided. with an individual trunkselecting' switch at the exchange, a line relay cont-rolling theoperation ot said switch, a switching relay for closing; contacts in theline circuit ailter said switch has operated, a cut-ott relay 'Fordisconnecting said line relay, a motor magnet for said switch, and anenergjizine` circuit 'tor the said cut-ott and switchingv relaysincluding` said motor magnet.

6. ln a telephone system, a line provided with an indii'idual trunltselecting' switch at the exchange, a. line relay controlling' theoperation oi? said switch, a switching' relay ttor closing' contacts inthe line circuit atter said switch has operated, a cut-oti1 relay 'tordisconnecting said line relay, a. motor maa'- net 'tor said switch, anenergizing' circuit iter the said cut-oil' and switching' relaysincluding' said motor nuignet, closed hv said line relay upon theinitial operation or said switch, and means'including` a test wiper otsaid switch ttor maintaining said cubed'l and switching relays shortcircuited during the trunk selecting operation.

7. lfn a telephone system, a line provided with an individual trunkselecting switch at the exchange, a. line relay controlling' theoperation of said switch, a switching relay for closing' contacts in theline circuit atter said switch has operated, a cut-oli rel y tordisconnectimesaid line relay, an energizing circuit for thel cut-ott andswitching' relays in series closed when the line is calling', and anenergizing circuit tor the cut-off relay alone closed when the line iscalledL 8. In a telephone system, trunk lines, an automatic trunkselecting switch controllable over a calling line y'to select an idletrunk, a differentially wound switching relay i'or closing the talkingconductors through said switch after the same has operated, circuits forthe two windings ot said relay maintained closed during the trunkselecting operation to preventsaid relay troni energizing, said circuitsbeing closed successively, and a Athird circuit 'tor the rel-ay windingincluded in said circuit which is closed last 'tor preventing said relayfrom energizing before the trunk selecting operation has started.

9. In a telephone system, trunk lines, an automatic trunk selectingswitch controllable over a calling line to select; an idle trunk, adifferentially wound switching relay for closing the talking conductorsthrough said switch after the same has operated, circuits for the twowindings of said relay maintained closed during the trunk selectingoperation to prevent said relay from energizing on a lousy trunk line, astepping niagnet for said switch, and contacts on said magnet foropening the circuit oli one winding to permit said relay to energizewhen an idle trunk line is reached.

l0. In a telephone system, trunk lines, an automatic switch controllableover a calling line to select an idle trunk, a differentially woundswitching relay for closing the linel conductors lthrough said switchlatter the same has operated, circuits for the two windings oi saidrelay closed before the trunk selecting operation is initiated, andmeans operated during the' selecting operation to open the circuit ofone winding of said relay as each successive trunk line is reached topermit its energization on any idle trunk line.

ll. In a telephone system, trunk lines, an automatic switch controllableover a calling line to select an idle trunk, a dilferentially woundswitching relay Yfor closing the lino conductors through said switchafter the same has operated, circuits for' the two windings ot saidrelay closed before thc trunk selecting operation is initiated, meansoperated during the selecting, operation to open the circuit of onewinding ci said relay. each successive trunk line is reached to permitits energization on any idle trunl; line, and test circuit connectionstor shunting said circuit opening means while the selector is passingbusy trunk lin-es.

12. In a telephone system, a plurality oi'x party lines, a plurality ofgroups ol con-- nectors, sets of fixed terminals for each station oneach line, the terminal sets associated with stations on the same linebeing in dili'erent groups ol connectors, and a plurality of sourceso'lringing current oi diiferent character associated with each group ot'connectors, together with rneans in each connector for selecting theproper source of ringing current and applying the same to the fixedterminals of a called station.

13. In a telephone system, plurality of party lines, signals at thestations on each line responsive to different frequencies olf ringingcurrent, a plurality of groups of connectors, sets ot fixed terminalsfor eac-h station on each line, the terminal sets associated withstations on the saine line being in different groups oi' connectors, aplurality of sources of ringing current of difierent frequencyassociated with each group of connectors, together with means in eachconnector for selecting the proper frequency of ringing current andapplying the same to the fixed terminals of a called station to actuatethe signal thereat.

lll. In a telephone system, a. plurality oi party lines, signals at thestations on each line responsive to diierent frequencies of ringingcurrent, a plurality of groups ot connectors, sets of iixed terminalsfor each station on each line, the terminal sets associated withstations on the same line being in different groups ot connectors, aplurality oit sources ot ringing current of dition ent frequencyassociated with each group ot connectors, frequency selecting andoperating mechanism in each connector, and means under control ol thesubscriber on a calling line Yfor extending connection to an idleconnector in one ot said groups, and ior controlling the mechanismthereotl to connect with and selectivelv. signal a wanted station.

l5. In a telephone. system, connector switch having a movable terminal,a party line accessible to said terminal via as many paths as there arestations on the line, means `lor operating said connector to adi/ance itto connect with said line, and mea-ns for pre-- determining over whichpath the connection is to be established.

16. In a telephone system, a connector switch iaving a movable terminal,a party line accessible to said terminal Via as many paths as there arestations on the line, a corresponding plurality of 'enerators cidiil'erent electrical character, .means in said connector t'or selectingone ol: said generators for connection to'said line via saidv movableterminal, and means for predetermin ing the path over which the selectedgeneris to be connected.

In a telephone system, a connector switch having a movable terminal, aparty line accessible to said t rniinal via as many paths as there arestations on the. line, means for operating said connector in accordancewith a digit in the call number oiZ said line to connect its terminalthereto, and means for predetermining in accordance with a previousdigit the path over which the connection is to be established.

18. ln a telephone system, an automatic connector switch having a pairor" line wipers, a party line accessible to said wipers via as manypaths as there are stations on the line, a corresponding plurality otgenerators ot dili'erent electrical character, means 'for connecting anygenerator wi-th said line via said wipers, and means in said connectorfor selecting a generator and for predetermining the path over which itis to be connected in accordance with a digit in t-he number ot saidline.

19. In a telephone system, an automatic connector switch, a party line,a plurality of stations on said line each provided with aset of iXedterminals in said connector, means for operating said connector toconnect with said line via any set ot iixed terminals, and selectiveringing mechanism in said connector responsive to a digit in `the callnumber off the wanted station on said line separate from the digit ordigits which control the operation of said connector.

20. ln a telephone system, an automatic connector switch provided with aset oi movable terminals, a party line provided with a set of fixedterminals in said connector tor each station on the line, sources ofringing current ot different character associated with said connector,means for transmitting' series of controlling impulses to said connectorin accordance with the digits in the call number or' a wanted station onsaid line, and mechanism in said connector responsive to one series ofimpulses for selecting one of said current sources while themovable'terminals oli said connector remain stationary in normalposition.

2l. In a telephone system, an automatic connector switch provided with aset o't movable terminals, a party line provided with a set of fixedterminals in said connector ior each station on the line, sources ot'ringing current ot different character associated with said connector,means for transmitting series ol controlling' impulses to said connectorin accordance with the digits in the call number oi a wanted station insaid line, mechanism in said connector responsive to one serios olimpulses li'or selecting one oi said current sources while the movableterminals ot said connector remain stationary in normal position, andoperating mechanism in said connector responsive to another series otimpulses for advancing said movable terminals into engagement with oneof said sets ot fixed terminals.

22. ln a telephone system, an automatic connector switch provided with aset oli movable terminals, a party line provided with a set of tiredterminals in said connector for each station on the line. sources ofringing current of ditte-rent character associated with said connector,means tor transmitting series or' controlling impulses to saidconnector' in accordance with the digits in the call number or' a wantedstation on said line, and mechanisms in said connector independentlycontrolled responsive to separate series oit impulses for selecting,respectively, the proper current source and a set ot said fixedterminals, in order to signal a desired station on said line.

23. ln a telephone system, an automatic connector switch, a party line,a plurality of stations on said line each provided with a set of lixedterminals in said connector, operating and selective ringing mechanismsin said connector, and means lor transmitting a plurality ot series ofcontrolling impulses to said connector in accordance with digits in thecall number ot a station on said line, said selective ringing mechanismbeing responsive to one series ot impulses and the said operatingmechanism being responsive to the remaining series oi impulses.

24. ln a telephone system, an automatic connector switch, a party line,a plurality of stations on said line each provided with a set of fixedterminals in said connector, operating and selective ringing mechanismsin a plurality of series o' controlling impulses to said connector inaccordance with digits in the call number a station on said line, and arelay responsive tothe iii-st series of impulses for controlling saidringing mechanism, and responsive to succeeding series o'll impulses torcontrolling the said operating mechanism.

25. ln a telephone system, an automatic connector switch, a party line,a. plurality ot stations on said line each provided with a set ot iixedterminals in said connector, operating and selective ringing mechanismsin said connector, and means iior transmitting a plurality ot' series oicont-rolling impulses to said connector in accordance with digits in thecall number oi a station on said line, the said ringingr mechanism andthe said operating n'icchanism being separately responsive to separateseries ot impulses.

26. in a telephone system, a party line connector switch, a pair ofringing generators ot different electrical character for selectivesignaling purposes, a line relay in said connector, and a second relayenergized in series with said Yline relay and under control of said linerelay for selecting either one or said generators.

27. In a tele )hone system, a party line connector switc operated inresponse to a said connector, means 'for transmitting plurality ofdigits of a called number, a pair of ringing generators oit diilerentelectrical character for selective signaling purposes. and a relay insaid connector controlled in accordance with the lirst otsaid digits andhaving contacts for connecting up eitherI generator for use.

28. ln a telephone system, a party line connector switch, a air ofringing` generators of dill'erent electrical character' for selectivesignaling purposes, a slow acting .relay in said connector. and ringingcircuit-s controlled by said relay for determining which of saidgenerators is to be used.

29. In a telephone system, a party line connector switch, a` pair ofringing generators of different electrical character 'for selectivesignaling purposes, a slow acting relay in said connector automaticallyenergized to select one of said generators, and means for deenergizingsaid relay to select the other generator.

30. In a telephone system, a party line connector switch, a pair o'lringing generators of different electrical character for selectivesignaling` purposes, a slow acting relay automatically energized toselect one oi.I said generators, and means responsive when a series olcontrolling` impulses is transmitted to said connector to deenergizesaid relay to select the other generator.

51. In a telephone system., a line terininating in an automatic switch,a stepping` relay and an operating magnet in said switch, a circuit forsaid relay including said line, a calling device operable in accordancewith digits in a called telephone number for producing interruptions insaid circuit to cause momentary deenergizations ot said relay, thenumber of interruptions produced being always equal to the digit called,and circuits controlled by said relay tor transmitting a current impulseto ,1 l Vina ,net at each deenergization and at each subsequentenergization.

232. ln a telephone system. an automatic switch. a stepping relay and anoperating' guet in said switch, means Jfor energizing and deenergizingsaid relay a plurality of imes, circuits controlled by said relay torinsmitting a current impulse to said magiA at each deeneigization and ateach enc gization, and mechanism for causing the impulse due to theenergization following the first deenergization to be omitted.

fl. ln a telephone system, an automatic atcb, a stepping relay and anoperating magnet in said switch, means for moment rily deene1,,`ing;said relay a plurality times in accordance with a digit in a calledtelephone number, circuits controlled by said relay for transmitting acurrent impulse to said magnet at each deenergization and at eachsubsequent energization,

there being mechanism for causing the ime pulse to be omitted on theinitial energize' tion of said relay, and mechanism controlled inaccordance with another digit in the number for causing another impulseto le omitted.

Bel. ln a telephone system, an automatic switca lor connecting callingand called lines, means for tr vnsmitting a plurality of series ofimpulses to said switch to operate the same, primary operating mechanismrespons've to one series of impulses for yancing said switch in a.number of steps equal to the number of impulses received, and secondaryoperating mechanism responsive to another series of impulses for furtheradvancing said switch in a number oi steps greater than the number ofimpulses received.

35, ln a telephone system, an automatic step by step switch forconnecting calling and called lines, means for transmitting a pluralityot series ot current impulses to said switch, operating mechanismresponsive to a series of impulses for advancing said switch a number ofsteps which is a multiple ot the number ot impulses in the series, andmechanism controlled in accordance with a previous series or impulsestor causing one step to be omitted in case the said previous seriescontained a particular' number of impulses.

ln a telephone system, an automatic step by step switch for connectingcalling and called lines, a line relay in said switch responsive to a`series of controlling impulses directed to said switch` a wiper shaft, amagnet controlled by said relay to advance saic shaft in a variablenumber ofsteps greater than the number of impulses in said series, asecond relay controlled according to a previous series of impulses, and

coonei-ating means controlled by said shaft and the said second relaytor determining the exact number oi steps said shaft is advanced.

3.7. ln a telephone system, means including an automaticy step by stepswitch for connecting a calling and called line, means for transmittingseries of impulses over the cal".ng line to control said switch, an opc1.ting magnet responsive to a series olf impulses to advance said switcha variable number of stepsr` and means for determining the numbero'ifsteps the switch will be so advanced.

ln a telephone system, means includingan automatic step by step switchfor connecting a calling and called line, means for transmitting seriesof impulses over the calling line to control said switch, an operatingvmagnet and means for actuating it a variable number of times in responseto any particular series ot impulses, and sepa- 'f means tor determiningthe number ot times sa'id magnet is to be actuate l ln telephonesystem., means includan automatic step by step switch Jfor crmnecting` acalling and called line, mcai Vt'or transmitting,` successive series or"iaj pulses over the calling line to control said switch, an operatingmacnet responsive to a particular series of impulses to advance saidswitch a certain number of steps, and second operating magnet responsiveto a likel series ot impulses to advance said switch a different numberof steps,

llt). ln a telephone system, an automatic switch, primary and secondaryoperating magnets in said switch, means for transmitting series otcontrolling,` impulses to said switch, a line relay responsive to aseries oic impulses :tor operating the primary magnet a number of times,and second relay responsive to a like series of impulses tor operatingthe secondary magnet a di'terent number ot times.

al. In a telephone system, an automatic switch, primary and secondaryoperating magnets in said switch, means iter transmit ling` series otcontrollingimpulses to said switch, a line relay responsive to a seriesot impulses for operating the primary magnet a number of times, and asecond relay responsive to a like series oit' impulses tor operating`the secondary magnet a greater number ot times.

42. ln a telephone system, an automatic switch, two groups ot lineterminals in said switch, the terminals oi one group alternating inposition with the terminals of the other group, a pair of ringinggenerators, a movable terminal in said switch, means 'tor operating themovable terminal to connect with a line terminal ot either group, andmeans dependent upon the selection ot a certain group of lines forselecting a particular one of said `generators.

4LP). ln a telephone system, an automatic switch, two groups of lineterminals in said switch so positioned that every two adjacent terminalsbelong to ditlerent groups, a pair of ringing' Agenerators, a movableterminal in said switch` means controlled over a call,- ing'subscribei"s line ttor advancing said movable terminal into engagementwith a desired line terminal in either group, and means dependent uponthe selection ot a certain group of lines tor selecting` a particularone ot said generators.

44. ln a telephone system, an automatic switch having a movableterminal, two series ot like numbered line terminals in said switch,means for transmitting two series of controlling impulses to saidswitch, and operating mechanism responsive to said impulses :toradvancing` said movable terminal past line terminals in both series andM with one of the two line erniinals which correspond to the series oi'impulses received.

ln a telephone system, an automatic switch having a movable terminal,two series of ke numbered line terminals in said switch, means tortransmitting two series of controlling iiipulses to said switch,operating mechanism responsive to sail impulses for advancing saidmovable terminal past line terminals in both series and into engagementwith one o't the two line terminals which correspond to the series ofimpulses received, and mans tor predetermining in accordance w h a priorseries oi impulses which line terminal is to be connected with.

4LP. ln a telephone system, an automatic switch, a series ot' calledline terminals in said switch numbered in accordance with the two linaldigits in telephone call numbers, a second series ot called lineterminals in said switch havin o like numbers with said first series,means for operating said switch in accordance with the two final digitsin a telephone call number to connect with a called line terminal ineither series, and relay mechanism operated in accordance with a priordigit in the telephone call number ior selecting' the series.

4l?. ln a telephone system, an automatic switch having' a movableterminal, two `groups oi" fixed te 'minals in said switch, means foroperating said switch to connect its movable terminal with a linedterminal in either group, an electromagnet in said switch and means.ifor energizingand deenergizingl it, and circuits controlled there- `iywhereby if said switch is operated when the magnet is energized aterminal in one group will be connect d with and whereby it' the switchis operated when the magnet deenergized a. terminal in another groupwill be connected with. i l

e8. ln a telephone system, an automatic switch, line terminals in saidswitch divided into groups, means tor transmitting' series otcontrolling impulses to said switch, and a slow acting relay in saidswitch responsive to a series of impulses to select a group ot saidterminals.

'-lQ. Aln a telephone system, an automatic switch, line terminals insaid switch divided into groups, means `for transmittingseries etcontrolling impulses to said switch, a slow acting, relay tor selecting`groups ot terminals, means for automatically energizine,` said relay`and means for deenergizing said relay in response to a particular seriesot impulses.

50. ln a telephone system, an automatic switch, line terminals in saidswitch divided into groups, means for transmitting series ot controllingimpulses .to said switch, a rento ennao'ement lay in said switchenergized automatically to select one group of said terminals, and meansfor deenergizing said relay to select another group of terminals inresponse to a particular' series ot impulses.

5l.. In a telephone system, an automatic switch, line terminals in saidswitch divided into groups, means tor transmitting series of controllingimpulses to said switch, and a relay in said switch responsive to oneseries ot impulses and irresponsive to another series of impulses fordetermining the selection ot a desired group ot said terminals.

52. ln a telephone system, an automatic switch, line terminals dividedinto groups and subgroups accessible to said connector, means fortransmitting three series of current impulses to said connector, relaysresponsive to one series having sole control of the group selection` andoperating magnets responsive to the two remaining series for selecting asubgroup in the selected group and an individual terminal in theselected subgroup.

53. In a telephone system, a party line connector switch, a pair ofringing generators oi' different electrical characters :tor selectivesignaling purposes, a line relay in said connector, a second relay undercontrol of said line relay, and means dependent on the energized ordeenergized position of said second relay for selecting either one ofsaid generators.

54. In a telephone system. an automatic switch, line terminals in saidswitch divided into groups, means vfor transmitting series ofcontrolling impulses to said switch, a line relay in said switch, aselecting device consisting solely of relays controlled by said linerelay responsive to the iirst series of impulses for selecting a desiredone ot said groups, a progressively movable switching mechanismcontrolled by said line relay responsive to another series of impulsesfor selecting a desired line in the selected group, and a circuitchanging device for shifting the control of said line relay from therelay selecting device to the switching mechanism.

55. In a telephone system, an automatic switch, line terminals in saidswitch divided into groups and subgroups, means for transmitting seriesof impulses to said switch, a line relay in said switch, a selectingdevice consisting solely ot relays controlled by said line relayresponsive to the lirst series of impulses for selecting a desired oneof said groups, a progressively movable switching mechanism controlledby said line relay responsive to the next series of impulses forselecting a desired subgroup in the selected group, anotherprogressively movable switching mechanism controlled by said line relayresponsive to the next series ot impulses tor selecting a desired linein the selected subgroup, and circuit changing means for shifting thecontrol of said line relay from the relay selecting device to the firstswitching mechanism and from the first switching mechanism to thesecond.

56. ln an automatic telephone system, a plurality oi party lines eachterminating in an automatic switch, said switches being operable toextend outgoing calls from said lines, means for distributing incomingcalls to the stations on said lines comprising groups ot connectorswitches, different classes of called line branches corresponding to thedifferent stations on a line, there being a plurality of branches oteach class accessible to the connectors ot eachV of said groups, adistributing trame whereat each party line may be connected at will withany desired branch in each of said classes, certain party lines beingeach connected to branches accessible to the same group ot connectorsand certain other party lines being each connected to branchesaccessible to different groups of connectors, and selective signallingmechanism in each connector in each group, whereby in the case of anyline whichhappens to be connected with a plurality of branches which areaccessible to the same group of connectors the. stations correspondingto such branches may be selectively signalled from any connector in thegroup.

57. In a telephone system, a plurality ot party lines incoming to anexchange, calling branches for said lines terminating in automaticswitches for use in extending outgoing calls, a plurality of lgroups otconnector switches, a plurality of called line branches terminating ineach group ot connectors, a permanent connection between each line andits associated calling branch, a distributing trame on which said partylines are temporarily connected to said called line branches by means ofjumpersn some lines being connected each to a plurality of branchesterminating in the same group of connectors and other lines beingconnected each to a plurality of branches terminating in dilerent groupsof connectors, and selective signaling means in each connector of eachgroup 'for signaling the station corresponding to any called branch towhich such connector has access.

58. In a telephone system, a line terminating in an automatic switch,trunk lines, means for controlling said switch over said line toautomatically select an idle trunk line, a differentially woundswitching relay for extending the said line to the selected trunk lineafter the switch has operated, an energizing circuit for said switchingrelay including one winding thereof, a second ci 1cuit including theother winding of said relay for preventing the relay from energizing,means for opening the said second circuit at the beginning of the trunkselecting operation, a test wiper for said switch, and a third circuitincluding said test wiper for shunting the lorealr in the said secondcircuit to prevent said relay from energizing until the trunk selectingoperation is com pleted.

59. ln a telephone system, trunk lines arranged in groups, a line'terminating in an automatic switch, means for directively controllingsaid switch over said line to select one of said trunk groups, means foroperating said. switch automatically to then selectan idle trunk in theselected group, a diilerentially wound switching relay for extending thesaid line to the selected trunk after t-he switch has operated, andcircuits for both windings of said relay maintained closed during theautomatic trunk selecting movement to prevent the energization of saidrelay.

60, ln a telephone system, trunk lines arranged in groups, a lineterminating in an automatic switch, means for directively centrollingsaid switch over said line to select one et said trunk groups, means foroperating said switch automatically to then select an idle trunk in theselected group, a diiierentially wound switching relay for eX- tendinojtrie said line te the selected trunk after tne switch has operated,anenergizing circuit for said switching relay including one windingthereof, a test wiper for said switch, and another circuit 'for saidrelay including the other winding thereof and said test wiper forpreventing the energization of said relay during the automatic trunkselecting operation.

Signed by me at Chicago, Cook County, illinois, this 22nd day of June,1917.

RCDNEY Gr. RICHARDSON.

